quartz-2d

I'm trying to animate the drawing of a line by the following way: .h CAShapeLayer *rootLayer; CAShapeLayer *lineLayer; CGMutablePathRef path; .m path = CGPathCreateMutable(); CGPathMoveToPoint(path, nil, self.frame.size.width/2-100, 260); CGPathAddLineToPoint(path, nil, self.frame.size.width/2+100.0, 260); CGPathCloseSubpath(path); self.rootLayer = [CALayer layer]; rootLayer.frame = self.bounds; [self.layer addSublayer:rootLayer]; self.lineLayer = [CAShapeLayer layer]; [lineLayer setPath:path]; [lineLayer setFillColor:[UIColor redColor].CGColor]; [lineLayer setStrokeColor:[UIColor blueColor]

I have the source code for a video decoder application written in C, which I'm now porting on iphone. My problem is as follows: I have RGBA pixel data for a frame in a buffer that I need to display on the screen. My buffer is of type unsigned char. (I cannot change it to any other data type as the source code is too huge and not written by me.) Most of the links I found on the net say about how to "draw and display pixels" on the screen or how to "display pixels present in an array", but none of then say how to "display pixel data present in a buffer". I'm planning to use quartz 2D. All I need

I'm developing an iPhone app with 3.1.3 SDK. I'm trying to draw a triangle with transparent fill an 1px black stroke with this code: CGContextMoveToPoint(ctx, position.X, position.Y - (size.height / 2)); CGContextAddLineToPoint(ctx, position.X - (size.width / 2), position.Y + (size.height / 2)); CGContextAddLineToPoint(ctx, position.X + (size.width / 2), position.Y + (size.height / 2)); CGContextFillPath(ctx); CGContextSetLineWidth(ctx, 1.0); CGContextStrokePath(ctx); CGContextSetFillColorWithColor(ctx, [[UIColor clearColor] CGColor]); But I get a black filled triangle. What am I doing wrong?

I wonder if anyone can help me with following. I have written a Quartz 2d ap and have used the following code to get the correct scale factor for each device : if ([UIScreen instancesRespondToSelector:@selector(scale)]) { return [[UIScreen mainScreen] scale]; } else { return 1.0; } I then multiply all values by this scale mulitplier in my code. The problem I have is that the app does not display propertly in x2 mode on the ipad - everything is two times too big. Can anybody help me ? Thanks, Martin Brad Larson The scale factor is related to the Retina displays on the newer iPhones and iPod

I'm curious as to the 'proper' method for achieving the following functionality using Quarts2D: I want to have a view, and to be able to add a circle at any coordinate. As soon as I add the circle it should expand at a predefined rate; I'd also like to repeat this process and have a number if these expanding circles. Think Missile Command: Generally, if I was writing this in C++ using SDL or some other graphics library I would: Have a class to represent an 'growing circle' Have a vector/array to hold pointers to all the 'growing circles' I create. All circles diameters would be increased each